Biathle is a sub sport of Modern Pentathlon. Biathle is an event that involves a run, swim, and run. It is a world class sport but not an Olympic one. The legs are raced with continuous transitions like triathlon. The race length is usually 200 m swim and 3 km run. A variant is Winter Biathle which has indoor swimming and does not have continuous transitions.

Originally invented to create opportunities for training the run and swim parts of pentathlon in real race conditions, Biathle has now developed into it's own sport expanding rapidly around the world.

The Biathle World Championships have been held in September or October annually since 1999. Approximately 800 athletes have competed at each edition of the championships, representing some 50 countries.